SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54804c7c4fc516183596d71527acbb73fbf67cf508c15eba07856174af5d9252' 
  AND token = '7aF4wz6fMVoDWKOzqq3BiRcyW/4A0JljU4G0mT2+GZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}